1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Ftrace header. For implementation details beyond the random comments
4 * scattered below, see: Documentation/trace/ftrace-design.rst
5 */
6
7 #ifndef _LINUX_FTRACE_H
8 #define _LINUX_FTRACE_H
9
10 #include <linux/trace_recursion.h>
11 #include <linux/trace_clock.h>
12 #include <linux/jump_label.h>
13 #include <linux/kallsyms.h>
14 #include <linux/linkage.h>
15 #include <linux/bitops.h>
16 #include <linux/ptrace.h>
17 #include <linux/ktime.h>
18 #include <linux/sched.h>
19 #include <linux/types.h>
20 #include <linux/init.h>
21 #include <linux/fs.h>
22
23 #include <asm/ftrace.h>
24
25 /*
26 * If the arch supports passing the variable contents of
27 * function_trace_op as the third parameter back from the
28 * mcount call, then the arch should define this as 1.
29 */
30 #ifndef ARCH_SUPPORTS_FTRACE_OPS
31 #define ARCH_SUPPORTS_FTRACE_OPS 0
32 #endif
33
34 #ifdef CONFIG_TRACING
35 extern void ftrace_boot_snapshot(void);
36 #else
ftrace_boot_snapshot(void)37 static inline void ftrace_boot_snapshot(void) { }
38 #endif
39
40 struct ftrace_ops;
41 struct ftrace_regs;
42 struct dyn_ftrace;
43
44 char *arch_ftrace_match_adjust(char *str, const char *search);
45
46 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
47 struct fgraph_ret_regs;
48 unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs);
49 #else
50 unsigned long ftrace_return_to_handler(unsigned long frame_pointer);
51 #endif
52
53 #ifdef CONFIG_FUNCTION_TRACER
54 /*
55 * If the arch's mcount caller does not support all of ftrace's
56 * features, then it must call an indirect function that
57 * does. Or at least does enough to prevent any unwelcome side effects.
58 *
59 * Also define the function prototype that these architectures use
60 * to call the ftrace_ops_list_func().
61 */
62 #if !ARCH_SUPPORTS_FTRACE_OPS
63 # define FTRACE_FORCE_LIST_FUNC 1
64 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
65 #else
66 # define FTRACE_FORCE_LIST_FUNC 0
67 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
68 struct ftrace_ops *op, struct ftrace_regs *fregs);
69 #endif
70 extern const struct ftrace_ops ftrace_nop_ops;
71 extern const struct ftrace_ops ftrace_list_ops;
72 struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec);
73 #endif /* CONFIG_FUNCTION_TRACER */
74
75 /* Main tracing buffer and events set up */
76 #ifdef CONFIG_TRACING
77 void trace_init(void);
78 void early_trace_init(void);
79 #else
trace_init(void)80 static inline void trace_init(void) { }
early_trace_init(void)81 static inline void early_trace_init(void) { }
82 #endif
83
84 struct module;
85 struct ftrace_hash;
86
87 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
88 defined(CONFIG_DYNAMIC_FTRACE)
89 const char *
90 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
91 unsigned long *off, char **modname, char *sym);
92 #else
93 static inline const char *
ftrace_mod_address_lookup(unsigned long addr,unsigned long * size,unsigned long * off,char ** modname,char * sym)94 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
95 unsigned long *off, char **modname, char *sym)
96 {
97 return NULL;
98 }
99 #endif
100
101 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
102 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
103 char *type, char *name,
104 char *module_name, int *exported);
105 #else
ftrace_mod_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)106 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
107 char *type, char *name,
108 char *module_name, int *exported)
109 {
110 return -1;
111 }
112 #endif
113
114 #ifdef CONFIG_FUNCTION_TRACER
115
116 extern int ftrace_enabled;
117
118 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
119
120 struct ftrace_regs {
121 struct pt_regs regs;
122 };
123 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
124
125 /*
126 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture
127 * if to allow setting of the instruction pointer from the ftrace_regs when
128 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching.
129 */
130 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0)
131 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
132
ftrace_get_regs(struct ftrace_regs * fregs)133 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
134 {
135 if (!fregs)
136 return NULL;
137
138 return arch_ftrace_get_regs(fregs);
139 }
140
141 /*
142 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
143 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
144 */
ftrace_regs_has_args(struct ftrace_regs * fregs)145 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs)
146 {
147 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS))
148 return true;
149
150 return ftrace_get_regs(fregs) != NULL;
151 }
152
153 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
154 #define ftrace_regs_get_instruction_pointer(fregs) \
155 instruction_pointer(ftrace_get_regs(fregs))
156 #define ftrace_regs_get_argument(fregs, n) \
157 regs_get_kernel_argument(ftrace_get_regs(fregs), n)
158 #define ftrace_regs_get_stack_pointer(fregs) \
159 kernel_stack_pointer(ftrace_get_regs(fregs))
160 #define ftrace_regs_return_value(fregs) \
161 regs_return_value(ftrace_get_regs(fregs))
162 #define ftrace_regs_set_return_value(fregs, ret) \
163 regs_set_return_value(ftrace_get_regs(fregs), ret)
164 #define ftrace_override_function_with_return(fregs) \
165 override_function_with_return(ftrace_get_regs(fregs))
166 #define ftrace_regs_query_register_offset(name) \
167 regs_query_register_offset(name)
168 #endif
169
170 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
171 struct ftrace_ops *op, struct ftrace_regs *fregs);
172
173 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
174
175 /*
176 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
177 * set in the flags member.
178 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
179 * IPMODIFY are a kind of attribute flags which can be set only before
180 * registering the ftrace_ops, and can not be modified while registered.
181 * Changing those attribute flags after registering ftrace_ops will
182 * cause unexpected results.
183 *
184 * ENABLED - set/unset when ftrace_ops is registered/unregistered
185 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
186 * allocated ftrace_ops which need special care
187 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
188 * and passed to the callback. If this flag is set, but the
189 * architecture does not support passing regs
190 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
191 * ftrace_ops will fail to register, unless the next flag
192 * is set.
193 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
194 * handler can handle an arch that does not save regs
195 * (the handler tests if regs == NULL), then it can set
196 * this flag instead. It will not fail registering the ftrace_ops
197 * but, the regs field will be NULL if the arch does not support
198 * passing regs to the handler.
199 * Note, if this flag is set, the SAVE_REGS flag will automatically
200 * get set upon registering the ftrace_ops, if the arch supports it.
201 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
202 * that the call back needs recursion protection. If it does
203 * not set this, then the ftrace infrastructure will assume
204 * that the callback can handle recursion on its own.
205 * STUB - The ftrace_ops is just a place holder.
206 * INITIALIZED - The ftrace_ops has already been initialized (first use time
207 * register_ftrace_function() is called, it will initialized the ops)
208 * DELETED - The ops are being deleted, do not let them be registered again.
209 * ADDING - The ops is in the process of being added.
210 * REMOVING - The ops is in the process of being removed.
211 * MODIFYING - The ops is in the process of changing its filter functions.
212 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
213 * The arch specific code sets this flag when it allocated a
214 * trampoline. This lets the arch know that it can update the
215 * trampoline in case the callback function changes.
216 * The ftrace_ops trampoline can be set by the ftrace users, and
217 * in such cases the arch must not modify it. Only the arch ftrace
218 * core code should set this flag.
219 * IPMODIFY - The ops can modify the IP register. This can only be set with
220 * SAVE_REGS. If another ops with this flag set is already registered
221 * for any of the functions that this ops will be registered for, then
222 * this ops will fail to register or set_filter_ip.
223 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
224 * RCU - Set when the ops can only be called when RCU is watching.
225 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
226 * PERMANENT - Set when the ops is permanent and should not be affected by
227 * ftrace_enabled.
228 * DIRECT - Used by the direct ftrace_ops helper for direct functions
229 * (internal ftrace only, should not be used by others)
230 */
231 enum {
232 FTRACE_OPS_FL_ENABLED = BIT(0),
233 FTRACE_OPS_FL_DYNAMIC = BIT(1),
234 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
235 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
236 FTRACE_OPS_FL_RECURSION = BIT(4),
237 FTRACE_OPS_FL_STUB = BIT(5),
238 FTRACE_OPS_FL_INITIALIZED = BIT(6),
239 FTRACE_OPS_FL_DELETED = BIT(7),
240 FTRACE_OPS_FL_ADDING = BIT(8),
241 FTRACE_OPS_FL_REMOVING = BIT(9),
242 FTRACE_OPS_FL_MODIFYING = BIT(10),
243 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
244 FTRACE_OPS_FL_IPMODIFY = BIT(12),
245 FTRACE_OPS_FL_PID = BIT(13),
246 FTRACE_OPS_FL_RCU = BIT(14),
247 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
248 FTRACE_OPS_FL_PERMANENT = BIT(16),
249 FTRACE_OPS_FL_DIRECT = BIT(17),
250 };
251
252 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
253 #define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS
254 #else
255 #define FTRACE_OPS_FL_SAVE_ARGS 0
256 #endif
257
258 /*
259 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
260 * to a ftrace_ops. Note, the requests may fail.
261 *
262 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same
263 * function as an ops with IPMODIFY. Called
264 * when the DIRECT ops is being registered.
265 * This is called with both direct_mutex and
266 * ftrace_lock are locked.
267 *
268 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same
269 * function as an ops with IPMODIFY. Called
270 * when the other ops (the one with IPMODIFY)
271 * is being registered.
272 * This is called with direct_mutex locked.
273 *
274 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same
275 * function as an ops with IPMODIFY. Called
276 * when the other ops (the one with IPMODIFY)
277 * is being unregistered.
278 * This is called with direct_mutex locked.
279 */
280 enum ftrace_ops_cmd {
281 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF,
282 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER,
283 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER,
284 };
285
286 /*
287 * For most ftrace_ops_cmd,
288 * Returns:
289 * 0 - Success.
290 * Negative on failure. The return value is dependent on the
291 * callback.
292 */
293 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd);
294
295 #ifdef CONFIG_DYNAMIC_FTRACE
296 /* The hash used to know what functions callbacks trace */
297 struct ftrace_ops_hash {
298 struct ftrace_hash __rcu *notrace_hash;
299 struct ftrace_hash __rcu *filter_hash;
300 struct mutex regex_lock;
301 };
302
303 void ftrace_free_init_mem(void);
304 void ftrace_free_mem(struct module *mod, void *start, void *end);
305 #else
ftrace_free_init_mem(void)306 static inline void ftrace_free_init_mem(void)
307 {
308 ftrace_boot_snapshot();
309 }
ftrace_free_mem(struct module * mod,void * start,void * end)310 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
311 #endif
312
313 /*
314 * Note, ftrace_ops can be referenced outside of RCU protection, unless
315 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
316 * core data, the unregistering of it will perform a scheduling on all CPUs
317 * to make sure that there are no more users. Depending on the load of the
318 * system that may take a bit of time.
319 *
320 * Any private data added must also take care not to be freed and if private
321 * data is added to a ftrace_ops that is in core code, the user of the
322 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
323 */
324 struct ftrace_ops {
325 ftrace_func_t func;
326 struct ftrace_ops __rcu *next;
327 unsigned long flags;
328 void *private;
329 ftrace_func_t saved_func;
330 #ifdef CONFIG_DYNAMIC_FTRACE
331 struct ftrace_ops_hash local_hash;
332 struct ftrace_ops_hash *func_hash;
333 struct ftrace_ops_hash old_hash;
334 unsigned long trampoline;
335 unsigned long trampoline_size;
336 struct list_head list;
337 ftrace_ops_func_t ops_func;
338 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
339 unsigned long direct_call;
340 #endif
341 #endif
342 };
343
344 extern struct ftrace_ops __rcu *ftrace_ops_list;
345 extern struct ftrace_ops ftrace_list_end;
346
347 /*
348 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
349 * can use rcu_dereference_raw_check() is that elements removed from this list
350 * are simply leaked, so there is no need to interact with a grace-period
351 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
352 * concurrent insertions into the ftrace_ops_list.
353 *
354 * Silly Alpha and silly pointer-speculation compiler optimizations!
355 */
356 #define do_for_each_ftrace_op(op, list) \
357 op = rcu_dereference_raw_check(list); \
358 do
359
360 /*
361 * Optimized for just a single item in the list (as that is the normal case).
362 */
363 #define while_for_each_ftrace_op(op) \
364 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
365 unlikely((op) != &ftrace_list_end))
366
367 /*
368 * Type of the current tracing.
369 */
370 enum ftrace_tracing_type_t {
371 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
372 FTRACE_TYPE_RETURN, /* Hook the return of the function */
373 };
374
375 /* Current tracing type, default is FTRACE_TYPE_ENTER */
376 extern enum ftrace_tracing_type_t ftrace_tracing_type;
377
378 /*
379 * The ftrace_ops must be a static and should also
380 * be read_mostly. These functions do modify read_mostly variables
381 * so use them sparely. Never free an ftrace_op or modify the
382 * next pointer after it has been registered. Even after unregistering
383 * it, the next pointer may still be used internally.
384 */
385 int register_ftrace_function(struct ftrace_ops *ops);
386 int unregister_ftrace_function(struct ftrace_ops *ops);
387
388 extern void ftrace_stub(unsigned long a0, unsigned long a1,
389 struct ftrace_ops *op, struct ftrace_regs *fregs);
390
391
392 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs);
393 #else /* !CONFIG_FUNCTION_TRACER */
394 /*
395 * (un)register_ftrace_function must be a macro since the ops parameter
396 * must not be evaluated.
397 */
398 #define register_ftrace_function(ops) ({ 0; })
399 #define unregister_ftrace_function(ops) ({ 0; })
ftrace_kill(void)400 static inline void ftrace_kill(void) { }
ftrace_free_init_mem(void)401 static inline void ftrace_free_init_mem(void) { }
ftrace_free_mem(struct module * mod,void * start,void * end)402 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
ftrace_lookup_symbols(const char ** sorted_syms,size_t cnt,unsigned long * addrs)403 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
404 {
405 return -EOPNOTSUPP;
406 }
407 #endif /* CONFIG_FUNCTION_TRACER */
408
409 struct ftrace_func_entry {
410 struct hlist_node hlist;
411 unsigned long ip;
412 unsigned long direct; /* for direct lookup only */
413 };
414
415 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
416 unsigned long ftrace_find_rec_direct(unsigned long ip);
417 int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
418 int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
419 bool free_filters);
420 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
421 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr);
422
423 void ftrace_stub_direct_tramp(void);
424
425 #else
426 struct ftrace_ops;
ftrace_find_rec_direct(unsigned long ip)427 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
428 {
429 return 0;
430 }
register_ftrace_direct(struct ftrace_ops * ops,unsigned long addr)431 static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
432 {
433 return -ENODEV;
434 }
unregister_ftrace_direct(struct ftrace_ops * ops,unsigned long addr,bool free_filters)435 static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
436 bool free_filters)
437 {
438 return -ENODEV;
439 }
modify_ftrace_direct(struct ftrace_ops * ops,unsigned long addr)440 static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
441 {
442 return -ENODEV;
443 }
modify_ftrace_direct_nolock(struct ftrace_ops * ops,unsigned long addr)444 static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
445 {
446 return -ENODEV;
447 }
448
449 /*
450 * This must be implemented by the architecture.
451 * It is the way the ftrace direct_ops helper, when called
452 * via ftrace (because there's other callbacks besides the
453 * direct call), can inform the architecture's trampoline that this
454 * routine has a direct caller, and what the caller is.
455 *
456 * For example, in x86, it returns the direct caller
457 * callback function via the regs->orig_ax parameter.
458 * Then in the ftrace trampoline, if this is set, it makes
459 * the return from the trampoline jump to the direct caller
460 * instead of going back to the function it just traced.
461 */
arch_ftrace_set_direct_caller(struct ftrace_regs * fregs,unsigned long addr)462 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
463 unsigned long addr) { }
464 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
465
466 #ifdef CONFIG_STACK_TRACER
467
468 extern int stack_tracer_enabled;
469
470 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
471 size_t *lenp, loff_t *ppos);
472
473 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
474 DECLARE_PER_CPU(int, disable_stack_tracer);
475
476 /**
477 * stack_tracer_disable - temporarily disable the stack tracer
478 *
479 * There's a few locations (namely in RCU) where stack tracing
480 * cannot be executed. This function is used to disable stack
481 * tracing during those critical sections.
482 *
483 * This function must be called with preemption or interrupts
484 * disabled and stack_tracer_enable() must be called shortly after
485 * while preemption or interrupts are still disabled.
486 */
stack_tracer_disable(void)487 static inline void stack_tracer_disable(void)
488 {
489 /* Preemption or interrupts must be disabled */
490 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
491 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
492 this_cpu_inc(disable_stack_tracer);
493 }
494
495 /**
496 * stack_tracer_enable - re-enable the stack tracer
497 *
498 * After stack_tracer_disable() is called, stack_tracer_enable()
499 * must be called shortly afterward.
500 */
stack_tracer_enable(void)501 static inline void stack_tracer_enable(void)
502 {
503 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
504 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
505 this_cpu_dec(disable_stack_tracer);
506 }
507 #else
stack_tracer_disable(void)508 static inline void stack_tracer_disable(void) { }
stack_tracer_enable(void)509 static inline void stack_tracer_enable(void) { }
510 #endif
511
512 #ifdef CONFIG_DYNAMIC_FTRACE
513
514 void ftrace_arch_code_modify_prepare(void);
515 void ftrace_arch_code_modify_post_process(void);
516
517 enum ftrace_bug_type {
518 FTRACE_BUG_UNKNOWN,
519 FTRACE_BUG_INIT,
520 FTRACE_BUG_NOP,
521 FTRACE_BUG_CALL,
522 FTRACE_BUG_UPDATE,
523 };
524 extern enum ftrace_bug_type ftrace_bug_type;
525
526 /*
527 * Archs can set this to point to a variable that holds the value that was
528 * expected at the call site before calling ftrace_bug().
529 */
530 extern const void *ftrace_expected;
531
532 void ftrace_bug(int err, struct dyn_ftrace *rec);
533
534 struct seq_file;
535
536 extern int ftrace_text_reserved(const void *start, const void *end);
537
538 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
539
540 bool is_ftrace_trampoline(unsigned long addr);
541
542 /*
543 * The dyn_ftrace record's flags field is split into two parts.
544 * the first part which is '0-FTRACE_REF_MAX' is a counter of
545 * the number of callbacks that have registered the function that
546 * the dyn_ftrace descriptor represents.
547 *
548 * The second part is a mask:
549 * ENABLED - the function is being traced
550 * REGS - the record wants the function to save regs
551 * REGS_EN - the function is set up to save regs.
552 * IPMODIFY - the record allows for the IP address to be changed.
553 * DISABLED - the record is not ready to be touched yet
554 * DIRECT - there is a direct function to call
555 * CALL_OPS - the record can use callsite-specific ops
556 * CALL_OPS_EN - the function is set up to use callsite-specific ops
557 * TOUCHED - A callback was added since boot up
558 * MODIFIED - The function had IPMODIFY or DIRECT attached to it
559 *
560 * When a new ftrace_ops is registered and wants a function to save
561 * pt_regs, the rec->flags REGS is set. When the function has been
562 * set up to save regs, the REG_EN flag is set. Once a function
563 * starts saving regs it will do so until all ftrace_ops are removed
564 * from tracing that function.
565 */
566 enum {
567 FTRACE_FL_ENABLED = (1UL << 31),
568 FTRACE_FL_REGS = (1UL << 30),
569 FTRACE_FL_REGS_EN = (1UL << 29),
570 FTRACE_FL_TRAMP = (1UL << 28),
571 FTRACE_FL_TRAMP_EN = (1UL << 27),
572 FTRACE_FL_IPMODIFY = (1UL << 26),
573 FTRACE_FL_DISABLED = (1UL << 25),
574 FTRACE_FL_DIRECT = (1UL << 24),
575 FTRACE_FL_DIRECT_EN = (1UL << 23),
576 FTRACE_FL_CALL_OPS = (1UL << 22),
577 FTRACE_FL_CALL_OPS_EN = (1UL << 21),
578 FTRACE_FL_TOUCHED = (1UL << 20),
579 FTRACE_FL_MODIFIED = (1UL << 19),
580 };
581
582 #define FTRACE_REF_MAX_SHIFT 19
583 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
584
585 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
586
587 struct dyn_ftrace {
588 unsigned long ip; /* address of mcount call-site */
589 unsigned long flags;
590 struct dyn_arch_ftrace arch;
591 };
592
593 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
594 int remove, int reset);
595 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
596 unsigned int cnt, int remove, int reset);
597 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
598 int len, int reset);
599 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
600 int len, int reset);
601 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
602 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
603 void ftrace_free_filter(struct ftrace_ops *ops);
604 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
605
606 enum {
607 FTRACE_UPDATE_CALLS = (1 << 0),
608 FTRACE_DISABLE_CALLS = (1 << 1),
609 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
610 FTRACE_START_FUNC_RET = (1 << 3),
611 FTRACE_STOP_FUNC_RET = (1 << 4),
612 FTRACE_MAY_SLEEP = (1 << 5),
613 };
614
615 /*
616 * The FTRACE_UPDATE_* enum is used to pass information back
617 * from the ftrace_update_record() and ftrace_test_record()
618 * functions. These are called by the code update routines
619 * to find out what is to be done for a given function.
620 *
621 * IGNORE - The function is already what we want it to be
622 * MAKE_CALL - Start tracing the function
623 * MODIFY_CALL - Stop saving regs for the function
624 * MAKE_NOP - Stop tracing the function
625 */
626 enum {
627 FTRACE_UPDATE_IGNORE,
628 FTRACE_UPDATE_MAKE_CALL,
629 FTRACE_UPDATE_MODIFY_CALL,
630 FTRACE_UPDATE_MAKE_NOP,
631 };
632
633 enum {
634 FTRACE_ITER_FILTER = (1 << 0),
635 FTRACE_ITER_NOTRACE = (1 << 1),
636 FTRACE_ITER_PRINTALL = (1 << 2),
637 FTRACE_ITER_DO_PROBES = (1 << 3),
638 FTRACE_ITER_PROBE = (1 << 4),
639 FTRACE_ITER_MOD = (1 << 5),
640 FTRACE_ITER_ENABLED = (1 << 6),
641 FTRACE_ITER_TOUCHED = (1 << 7),
642 FTRACE_ITER_ADDRS = (1 << 8),
643 };
644
645 void arch_ftrace_update_code(int command);
646 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
647 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
648 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
649
650 struct ftrace_rec_iter;
651
652 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
653 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
654 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
655
656 #define for_ftrace_rec_iter(iter) \
657 for (iter = ftrace_rec_iter_start(); \
658 iter; \
659 iter = ftrace_rec_iter_next(iter))
660
661
662 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
663 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
664 void ftrace_run_stop_machine(int command);
665 unsigned long ftrace_location(unsigned long ip);
666 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
667 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
668 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
669
670 extern ftrace_func_t ftrace_trace_function;
671
672 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
673 struct inode *inode, struct file *file);
674 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
675 size_t cnt, loff_t *ppos);
676 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
677 size_t cnt, loff_t *ppos);
678 int ftrace_regex_release(struct inode *inode, struct file *file);
679
680 void __init
681 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
682
683 /* defined in arch */
684 extern int ftrace_dyn_arch_init(void);
685 extern void ftrace_replace_code(int enable);
686 extern int ftrace_update_ftrace_func(ftrace_func_t func);
687 extern void ftrace_caller(void);
688 extern void ftrace_regs_caller(void);
689 extern void ftrace_call(void);
690 extern void ftrace_regs_call(void);
691 extern void mcount_call(void);
692
693 void ftrace_modify_all_code(int command);
694
695 #ifndef FTRACE_ADDR
696 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
697 #endif
698
699 #ifndef FTRACE_GRAPH_ADDR
700 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
701 #endif
702
703 #ifndef FTRACE_REGS_ADDR
704 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
705 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
706 #else
707 # define FTRACE_REGS_ADDR FTRACE_ADDR
708 #endif
709 #endif
710
711 /*
712 * If an arch would like functions that are only traced
713 * by the function graph tracer to jump directly to its own
714 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
715 * to be that address to jump to.
716 */
717 #ifndef FTRACE_GRAPH_TRAMP_ADDR
718 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
719 #endif
720
721 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
722 extern void ftrace_graph_caller(void);
723 extern int ftrace_enable_ftrace_graph_caller(void);
724 extern int ftrace_disable_ftrace_graph_caller(void);
725 #else
ftrace_enable_ftrace_graph_caller(void)726 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
ftrace_disable_ftrace_graph_caller(void)727 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
728 #endif
729
730 /**
731 * ftrace_make_nop - convert code into nop
732 * @mod: module structure if called by module load initialization
733 * @rec: the call site record (e.g. mcount/fentry)
734 * @addr: the address that the call site should be calling
735 *
736 * This is a very sensitive operation and great care needs
737 * to be taken by the arch. The operation should carefully
738 * read the location, check to see if what is read is indeed
739 * what we expect it to be, and then on success of the compare,
740 * it should write to the location.
741 *
742 * The code segment at @rec->ip should be a caller to @addr
743 *
744 * Return must be:
745 * 0 on success
746 * -EFAULT on error reading the location
747 * -EINVAL on a failed compare of the contents
748 * -EPERM on error writing to the location
749 * Any other value will be considered a failure.
750 */
751 extern int ftrace_make_nop(struct module *mod,
752 struct dyn_ftrace *rec, unsigned long addr);
753
754 /**
755 * ftrace_need_init_nop - return whether nop call sites should be initialized
756 *
757 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
758 * need to call ftrace_init_nop() if the code is built with that flag.
759 * Architectures where this is not always the case may define their own
760 * condition.
761 *
762 * Return must be:
763 * 0 if ftrace_init_nop() should be called
764 * Nonzero if ftrace_init_nop() should not be called
765 */
766
767 #ifndef ftrace_need_init_nop
768 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
769 #endif
770
771 /**
772 * ftrace_init_nop - initialize a nop call site
773 * @mod: module structure if called by module load initialization
774 * @rec: the call site record (e.g. mcount/fentry)
775 *
776 * This is a very sensitive operation and great care needs
777 * to be taken by the arch. The operation should carefully
778 * read the location, check to see if what is read is indeed
779 * what we expect it to be, and then on success of the compare,
780 * it should write to the location.
781 *
782 * The code segment at @rec->ip should contain the contents created by
783 * the compiler
784 *
785 * Return must be:
786 * 0 on success
787 * -EFAULT on error reading the location
788 * -EINVAL on a failed compare of the contents
789 * -EPERM on error writing to the location
790 * Any other value will be considered a failure.
791 */
792 #ifndef ftrace_init_nop
ftrace_init_nop(struct module * mod,struct dyn_ftrace * rec)793 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
794 {
795 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
796 }
797 #endif
798
799 /**
800 * ftrace_make_call - convert a nop call site into a call to addr
801 * @rec: the call site record (e.g. mcount/fentry)
802 * @addr: the address that the call site should call
803 *
804 * This is a very sensitive operation and great care needs
805 * to be taken by the arch. The operation should carefully
806 * read the location, check to see if what is read is indeed
807 * what we expect it to be, and then on success of the compare,
808 * it should write to the location.
809 *
810 * The code segment at @rec->ip should be a nop
811 *
812 * Return must be:
813 * 0 on success
814 * -EFAULT on error reading the location
815 * -EINVAL on a failed compare of the contents
816 * -EPERM on error writing to the location
817 * Any other value will be considered a failure.
818 */
819 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
820
821 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \
822 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) || \
823 defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)
824 /**
825 * ftrace_modify_call - convert from one addr to another (no nop)
826 * @rec: the call site record (e.g. mcount/fentry)
827 * @old_addr: the address expected to be currently called to
828 * @addr: the address to change to
829 *
830 * This is a very sensitive operation and great care needs
831 * to be taken by the arch. The operation should carefully
832 * read the location, check to see if what is read is indeed
833 * what we expect it to be, and then on success of the compare,
834 * it should write to the location.
835 *
836 * When using call ops, this is called when the associated ops change, even
837 * when (addr == old_addr).
838 *
839 * The code segment at @rec->ip should be a caller to @old_addr
840 *
841 * Return must be:
842 * 0 on success
843 * -EFAULT on error reading the location
844 * -EINVAL on a failed compare of the contents
845 * -EPERM on error writing to the location
846 * Any other value will be considered a failure.
847 */
848 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
849 unsigned long addr);
850 #else
851 /* Should never be called */
ftrace_modify_call(struct dyn_ftrace * rec,unsigned long old_addr,unsigned long addr)852 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
853 unsigned long addr)
854 {
855 return -EINVAL;
856 }
857 #endif
858
859 extern int skip_trace(unsigned long ip);
860 extern void ftrace_module_init(struct module *mod);
861 extern void ftrace_module_enable(struct module *mod);
862 extern void ftrace_release_mod(struct module *mod);
863 #else /* CONFIG_DYNAMIC_FTRACE */
skip_trace(unsigned long ip)864 static inline int skip_trace(unsigned long ip) { return 0; }
ftrace_module_init(struct module * mod)865 static inline void ftrace_module_init(struct module *mod) { }
ftrace_module_enable(struct module * mod)866 static inline void ftrace_module_enable(struct module *mod) { }
ftrace_release_mod(struct module * mod)867 static inline void ftrace_release_mod(struct module *mod) { }
ftrace_text_reserved(const void * start,const void * end)868 static inline int ftrace_text_reserved(const void *start, const void *end)
869 {
870 return 0;
871 }
ftrace_location(unsigned long ip)872 static inline unsigned long ftrace_location(unsigned long ip)
873 {
874 return 0;
875 }
876
877 /*
878 * Again users of functions that have ftrace_ops may not
879 * have them defined when ftrace is not enabled, but these
880 * functions may still be called. Use a macro instead of inline.
881 */
882 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
883 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
884 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
885 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
886 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
887 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
888 #define ftrace_free_filter(ops) do { } while (0)
889 #define ftrace_ops_set_global_filter(ops) do { } while (0)
890
ftrace_filter_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)891 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
892 size_t cnt, loff_t *ppos) { return -ENODEV; }
ftrace_notrace_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)893 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
894 size_t cnt, loff_t *ppos) { return -ENODEV; }
895 static inline int
ftrace_regex_release(struct inode * inode,struct file * file)896 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
897
is_ftrace_trampoline(unsigned long addr)898 static inline bool is_ftrace_trampoline(unsigned long addr)
899 {
900 return false;
901 }
902 #endif /* CONFIG_DYNAMIC_FTRACE */
903
904 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
905 #ifndef ftrace_graph_func
906 #define ftrace_graph_func ftrace_stub
907 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
908 #else
909 #define FTRACE_OPS_GRAPH_STUB 0
910 #endif
911 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
912
913 /* totally disable ftrace - can not re-enable after this */
914 void ftrace_kill(void);
915
tracer_disable(void)916 static inline void tracer_disable(void)
917 {
918 #ifdef CONFIG_FUNCTION_TRACER
919 ftrace_enabled = 0;
920 #endif
921 }
922
923 /*
924 * Ftrace disable/restore without lock. Some synchronization mechanism
925 * must be used to prevent ftrace_enabled to be changed between
926 * disable/restore.
927 */
__ftrace_enabled_save(void)928 static inline int __ftrace_enabled_save(void)
929 {
930 #ifdef CONFIG_FUNCTION_TRACER
931 int saved_ftrace_enabled = ftrace_enabled;
932 ftrace_enabled = 0;
933 return saved_ftrace_enabled;
934 #else
935 return 0;
936 #endif
937 }
938
__ftrace_enabled_restore(int enabled)939 static inline void __ftrace_enabled_restore(int enabled)
940 {
941 #ifdef CONFIG_FUNCTION_TRACER
942 ftrace_enabled = enabled;
943 #endif
944 }
945
946 /* All archs should have this, but we define it for consistency */
947 #ifndef ftrace_return_address0
948 # define ftrace_return_address0 __builtin_return_address(0)
949 #endif
950
951 /* Archs may use other ways for ADDR1 and beyond */
952 #ifndef ftrace_return_address
953 # ifdef CONFIG_FRAME_POINTER
954 # define ftrace_return_address(n) __builtin_return_address(n)
955 # else
956 # define ftrace_return_address(n) 0UL
957 # endif
958 #endif
959
960 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
961 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
962 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
963 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
964 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
965 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
966 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
967
get_lock_parent_ip(void)968 static __always_inline unsigned long get_lock_parent_ip(void)
969 {
970 unsigned long addr = CALLER_ADDR0;
971
972 if (!in_lock_functions(addr))
973 return addr;
974 addr = CALLER_ADDR1;
975 if (!in_lock_functions(addr))
976 return addr;
977 return CALLER_ADDR2;
978 }
979
980 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
981 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
982 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
983 #else
984 /*
985 * Use defines instead of static inlines because some arches will make code out
986 * of the CALLER_ADDR, when we really want these to be a real nop.
987 */
988 # define trace_preempt_on(a0, a1) do { } while (0)
989 # define trace_preempt_off(a0, a1) do { } while (0)
990 #endif
991
992 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
993 extern void ftrace_init(void);
994 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
995 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
996 #else
997 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
998 #endif
999 #else
ftrace_init(void)1000 static inline void ftrace_init(void) { }
1001 #endif
1002
1003 /*
1004 * Structure that defines an entry function trace.
1005 * It's already packed but the attribute "packed" is needed
1006 * to remove extra padding at the end.
1007 */
1008 struct ftrace_graph_ent {
1009 unsigned long func; /* Current function */
1010 int depth;
1011 } __packed;
1012
1013 /*
1014 * Structure that defines a return function trace.
1015 * It's already packed but the attribute "packed" is needed
1016 * to remove extra padding at the end.
1017 */
1018 struct ftrace_graph_ret {
1019 unsigned long func; /* Current function */
1020 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL
1021 unsigned long retval;
1022 #endif
1023 int depth;
1024 /* Number of functions that overran the depth limit for current task */
1025 unsigned int overrun;
1026 unsigned long long calltime;
1027 unsigned long long rettime;
1028 } __packed;
1029
1030 /* Type of the callback handlers for tracing function graph*/
1031 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
1032 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
1033
1034 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
1035
1036 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1037
1038 struct fgraph_ops {
1039 trace_func_graph_ent_t entryfunc;
1040 trace_func_graph_ret_t retfunc;
1041 };
1042
1043 /*
1044 * Stack of return addresses for functions
1045 * of a thread.
1046 * Used in struct thread_info
1047 */
1048 struct ftrace_ret_stack {
1049 unsigned long ret;
1050 unsigned long func;
1051 unsigned long long calltime;
1052 #ifdef CONFIG_FUNCTION_PROFILER
1053 unsigned long long subtime;
1054 #endif
1055 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
1056 unsigned long fp;
1057 #endif
1058 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
1059 unsigned long *retp;
1060 #endif
1061 };
1062
1063 /*
1064 * Primary handler of a function return.
1065 * It relays on ftrace_return_to_handler.
1066 * Defined in entry_32/64.S
1067 */
1068 extern void return_to_handler(void);
1069
1070 extern int
1071 function_graph_enter(unsigned long ret, unsigned long func,
1072 unsigned long frame_pointer, unsigned long *retp);
1073
1074 struct ftrace_ret_stack *
1075 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
1076
1077 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1078 unsigned long ret, unsigned long *retp);
1079
1080 /*
1081 * Sometimes we don't want to trace a function with the function
1082 * graph tracer but we want them to keep traced by the usual function
1083 * tracer if the function graph tracer is not configured.
1084 */
1085 #define __notrace_funcgraph notrace
1086
1087 #define FTRACE_RETFUNC_DEPTH 50
1088 #define FTRACE_RETSTACK_ALLOC_SIZE 32
1089
1090 extern int register_ftrace_graph(struct fgraph_ops *ops);
1091 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1092
1093 /**
1094 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
1095 *
1096 * ftrace_graph_stop() is called when a severe error is detected in
1097 * the function graph tracing. This function is called by the critical
1098 * paths of function graph to keep those paths from doing any more harm.
1099 */
1100 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
1101
ftrace_graph_is_dead(void)1102 static inline bool ftrace_graph_is_dead(void)
1103 {
1104 return static_branch_unlikely(&kill_ftrace_graph);
1105 }
1106
1107 extern void ftrace_graph_stop(void);
1108
1109 /* The current handlers in use */
1110 extern trace_func_graph_ret_t ftrace_graph_return;
1111 extern trace_func_graph_ent_t ftrace_graph_entry;
1112
1113 extern void ftrace_graph_init_task(struct task_struct *t);
1114 extern void ftrace_graph_exit_task(struct task_struct *t);
1115 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1116
pause_graph_tracing(void)1117 static inline void pause_graph_tracing(void)
1118 {
1119 atomic_inc(¤t->tracing_graph_pause);
1120 }
1121
unpause_graph_tracing(void)1122 static inline void unpause_graph_tracing(void)
1123 {
1124 atomic_dec(¤t->tracing_graph_pause);
1125 }
1126 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1127
1128 #define __notrace_funcgraph
1129
ftrace_graph_init_task(struct task_struct * t)1130 static inline void ftrace_graph_init_task(struct task_struct *t) { }
ftrace_graph_exit_task(struct task_struct * t)1131 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
ftrace_graph_init_idle_task(struct task_struct * t,int cpu)1132 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1133
1134 /* Define as macros as fgraph_ops may not be defined */
1135 #define register_ftrace_graph(ops) ({ -1; })
1136 #define unregister_ftrace_graph(ops) do { } while (0)
1137
1138 static inline unsigned long
ftrace_graph_ret_addr(struct task_struct * task,int * idx,unsigned long ret,unsigned long * retp)1139 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1140 unsigned long *retp)
1141 {
1142 return ret;
1143 }
1144
pause_graph_tracing(void)1145 static inline void pause_graph_tracing(void) { }
unpause_graph_tracing(void)1146 static inline void unpause_graph_tracing(void) { }
1147 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1148
1149 #ifdef CONFIG_TRACING
1150 enum ftrace_dump_mode;
1151
1152 #define MAX_TRACER_SIZE 100
1153 extern char ftrace_dump_on_oops[];
1154 extern int ftrace_dump_on_oops_enabled(void);
1155 extern int tracepoint_printk;
1156
1157 extern void disable_trace_on_warning(void);
1158 extern int __disable_trace_on_warning;
1159
1160 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1161 void *buffer, size_t *lenp, loff_t *ppos);
1162
1163 #else /* CONFIG_TRACING */
disable_trace_on_warning(void)1164 static inline void disable_trace_on_warning(void) { }
1165 #endif /* CONFIG_TRACING */
1166
1167 #ifdef CONFIG_FTRACE_SYSCALLS
1168
1169 unsigned long arch_syscall_addr(int nr);
1170
1171 #endif /* CONFIG_FTRACE_SYSCALLS */
1172
1173 #endif /* _LINUX_FTRACE_H */
1174